Tracked vehicles such as tanks or bulldozers are conventionally steered by moving the tracks on one side of the vehicle faster than the tracks on the other side of the vehicle. Such vehicles typically have steering systems which include various combinations of differential gears, clutches and brakes arranged so that the drive wheel for one track can be clutched or braked independently of the drive wheel for the other track. Such steering systems tend to add weight, space requirements and cost to the vehicles. Other tracked vehicles may have two separate drive trains connected to the vehicle engine, one drive train for each track. Having two drive trains also adds weight, space requirements and cost to the tracked vehicles.
In view of the above problems, what I propose is a differential gearbox style of steering mechanism that requires only one drive train component. My steering mechanism has an input gear for receiving power from the vehicle drive train and two output shafts, one for each drive wheel or track of the vehicle. Selectively actuatable bearing rings on the exterior of the differential gearbox interact with pinion gears that determine the amount of relative movement between the output shafts.
My steering mechanism can be part of a system that limits the speed differential between the output shafts. The speed differential between drive wheel or tracks of the vehicle are thus limited so that the vehicle has better traction on snow, mud or other slippery surfaces. Such a system includes sensors to detect the rotational speed of the output shafts and logic circuitry to compare the speeds. The logic circuitry sends signals to operate a means for actuating the bearing rings when the difference in speeds exceeds a selected limit. dr